| [ Summary ] |
Twenty years ago, laser endoscopy appeared as the first endoscopic treatment and has contributed to the development of this type of treatment, However, this treatment which used heat energy of high power laser promoted to use of other methods, such as electocoagulation,or microwave coagulation. And the application of laser for endoscopic treatment has been gradually limited to specific cases, in which there are difficulties in performing operations and for endoscopic mucosectomy. At present, photodynamic therapy and photodynamic diagnosis of cancers are mainly being studied as the medical application of laser in the second generation,using low power laser systems and a fluorescence dye which can be absorbed in a targeted tumor tissue. And many new photosensitizers are capable of accumulating in malignant tumors more selectively, and new diode laser systems, releasing beams of longer wave lengths, which can reach deeper tissue, are being developed. |